The Lupus Genetics Studies and Lupus Family Registry &Repository are working to find the genes that reveal the causes of systemic lupus erythematosus (SLE, or lupus). The study is enrolling families of all ethnic backgrounds from the United States and other countries that have one or more living members diagnosed with SLE. SLE is an often crippling and potentially fatal autoimmune disease that is nine times more prevalent in women than in men, and four times more likely to affect African American females than Caucasian females. It is suspected that a genetic predisposition along with environmental factors contribute to the clinical manifestation of SLE. The Lupus Genetics Studies consist of several familial SLE studies, including the Lupus Family Registry &Repository (LFRR, formerly known as the Lupus Multiplex Registry &Repository, or LMRR). The Lupus Studies enroll families of all ethnicities with one or more members diagnosed with systemic lupus to determine what genes contribute to the development of the disease. Additionally, the Lupus Family Registry &Repository is the largest repository of its kind in North America. In addition to the research done on site, the Repository serves as a national resource for scientists interested in conducting research on SLE and families either simplex or multiplex for lupus. Data, serum samples, and DNA samples are available to researchers. By collecting families in which two or more living individuals have been diagnosed with SLE, the study is utilizing the genetic link between the affected family members to discover disease-associated genes. Records will be requested from the patients'treating physicians to document various lupus symptoms and related problems. One-time blood samples will be collected from the patients as well as from certain family members and an unrelated volunteer. There is no cost to participate and the study pays for sample draws and shipping.